Mobile Robot Localization Problem Research Articles

Measurement outlier-resistant mobile robot localization using multiple Doppler-azimuth radars under round-robin protocol

This paper is concerned with the measurement outlier-resistant mobile robot localization problem by using multiple Doppler-azimuth radars under round-robin protocol (R-RP). In the considered robot localization system, multiple Doppler-azimuth radars are equipped on the robot platform to produce the measurement including the Doppler frequency shift and the azimuth. In order to assuage communication link congestion, the R-RP is used. For mitigating the influence of outliers, a time-varying state estimator is constructed which contains a saturation function with variable saturation levels. This paper aims at seeking out a practicable yet effective solution to the addressed robot localization problem by devising the constructed estimator which can assure that, over a finite horizon, the localization error satisfies the given H∞ performance index. By constructing an appropriate Lyapunov function, the sufficient condition, which can guarantee the localization error to fulfill the given H∞ performance, is established. Then, by resorting to the solution to a set of linear matrix inequalities, the constructed estimator can be devised. In the light of the estimator design strategy proposed in this paper, the corresponding robot localization algorithm is developed. At last, some simulations are conducted to testify the usefulness of the developed robot localization algorithm.

Robust State and Unknown Input Estimator and Its Application to Robot Localization

The robot localization problem is typically solved using state estimation techniques, where process and sensing inaccuracies are invariably present. Moreover, disturbances in the sensing and actuating mechanisms add to the uncertainties. Any system may degrade over time, and its parameter values may be ambivalently known. Cumulatively, all these sources of errors and uncertainties are considered as unknown inputs. This work aims to address the unknown inputs using a robust state (pose in the robot localization problem) estimator. The proposed robust state estimator deals with the unknown inputs such that the solution of the estimator is constrained in a way that warrants unbiased state estimates in the presence of the unknown inputs. This article explores the formulation of these constraints and the development of a constrained state estimator for a system, where the unknown inputs appear in both the state transition map (i.e., system model) and the state-output map (i.e., measurement model). The theoretical development of such a strategy stems from the localization problem of a wheeled mobile robot. The residuals of the constrained state estimator developed contain information about the unknown inputs. We conceive a recursive least squares strategy to estimate the unknown inputs simultaneously with the states using this information. Using simulations and experimental studies, we demonstrate the adequacy of our strategy for a differential drive robot.

Recursive filtering for mobile robot localization under an energy harvesting sensor

AbstractIn this paper, the localization problem of the mobile robot (MR) with an energy harvesting sensor (EHS) is studied. A specific situation is regarded, which is that the MR equips with an EHS who owns the capacity for absorbing the energy from the surroundings. When the sensor energy is sufficient, the sensor can send its measurement to the filter. Otherwise, the sensor energy‐induced measurement missing phenomenon will occur. For the sake of acquiring the measurement missing rate, the relationship between the amount of the sensor energy and its probability distribution is derived recursively at each time instant. The purpose of this paper is to seek out a feasible solution to the addressed MR localization (MRL) problem (MRLP) by devising the desired time‐varying filter. Firstly, in the presence of the sensor energy‐induced measurement missing phenomenon, an upper bound (UB) for the filtering error (FE) covariance (FEC) is acquired recursively. Then, the acquired UB is minimized by characterizing the desired filter gain adequately. Finally, a simulation is conducted to testify the availability of the proposed MRL algorithm (MRLA).

Recursive fusion estimation for mobile robot localization under multiple energy harvesting sensors

This paper is concerned with the recursive fusion estimation-based mobile robot localization (RL) problem by employing multiple energy harvesting sensors (EHSs). In the addressed RL problem, multiple sensors with energy harvesting capacity are deployed to produce measurements used for RL. When the sensors own sufficient energy, the sensors can output measurements and then send them to the corresponding local filter. Otherwise, the sensor energy-induced missing measurement phenomenon will occur. In order to obtain the missing measurement rate, at each time instant, the relationship between the totality of the sensor energy and its probability distribution is derived recursively. This paper aims at seeking out a practicable solution to the addressed mobile RL problem. First, in the presence of the sensor energy-induced measurement missing phenomenon, an upper bound (UB) of the local localization error covariance is recursively acquired. Then, such a derived UB is minimized by suitably devising the desired local filter parameter. Subsequently, the covariance intersection fusion method is adopted to achieve the addressed RL problem. In the end, a simulation is conducted to verify the practicability of the developed RL scheme.

Variance‐constrained resilient H∞ filtering for mobile robot localization under dynamic event‐triggered communication mechanism

AbstractThis paper is concerned with the mobile robot localization problem subject to filter gain uncertainty under dynamic event‐triggered communication mechanism, and meanwhile, the H∞ filtering performance and the error variance constraint are guaranteed. For saving the sensor energy, a dynamic event‐triggered communication mechanism is introduced to manage the transmission of the measurement data from the sensor to the filter. To characterize the possible fluctuations of the desired filter gain, a resilient filter is constructed for the mobile robot localization. The aim of this paper is to find a solution to the mobile robot localization problem by designing a nonlinear resilient filter such that the filtering error dynamics satisfies both the H∞ performance requirement and the error variance constraint over a finite time horizon simultaneously. By resorting to the Lyapunov theory and the stochastic analysis technique, the sufficient conditions are established to guarantee that the error dynamic system satisfies both the H∞ performance requirement and the error variance constraint. Then, a recursive linear matrix inequality (RLMI) approach is employed to design the desired filter. Based on the proposed filter design scheme, the corresponding localization algorithm is presented. Finally, an experiment is conducted in the simulation environment to verify the effectiveness of the proposed localization algorithm.

Robust Localization of the Mobile Robot Driven by Lidar Measurement and Matching for Ongoing Scene

Aiming at the localization problem of mobile robot in construction scenes, a hybrid localization algorithm with the adaptive weights is proposed, which can effectively improve the robust localization of mobile robot. Firstly, two indicators of localization accuracy and calculation efficiency are set to reflect the robustness of localization. Secondly, the construction scene is defined as an ongoing scene, and the robust localization of mobile robot is achieved by using the measurement of artificial landmarks and matching based on generated features. Finally, the experimental results show that the accuracy of localization is up to 8.22 mm and the most matching efficiency is controlled within 0.027 s. The hybrid localization algorithm that based on adaptive weights can realize a good robustness for tasks such as autonomous navigation and path planning in construction scenes.

Model-based kernel sum rule: kernel Bayesian inference with probabilistic models

Kernel Bayesian inference is a principled approach to nonparametric inference in probabilistic graphical models, where probabilistic relationships between variables are learned from data in a nonparametric manner. Various algorithms of kernel Bayesian inference have been developed by combining kernelized basic probabilistic operations such as the kernel sum rule and kernel Bayes’ rule. However, the current framework is fully nonparametric, and it does not allow a user to flexibly combine nonparametric and model-based inferences. This is inefficient when there are good probabilistic models (or simulation models) available for some parts of a graphical model; this is in particular true in scientific fields where “models” are the central topic of study. Our contribution in this paper is to introduce a novel approach, termed the model-based kernel sum rule (Mb-KSR), to combine a probabilistic model and kernel Bayesian inference. By combining the Mb-KSR with the existing kernelized probabilistic rules, one can develop various algorithms for hybrid (i.e., nonparametric and model-based) inferences. As an illustrative example, we consider Bayesian filtering in a state space model, where typically there exists an accurate probabilistic model for the state transition process. We propose a novel filtering method that combines model-based inference for the state transition process and data-driven, nonparametric inference for the observation generating process. We empirically validate our approach with synthetic and real-data experiments, the latter being the problem of vision-based mobile robot localization in robotics, which illustrates the effectiveness of the proposed hybrid approach.

Improving Visual Localization Accuracy in Dynamic Environments Based on Dynamic Region Removal

Visual localization is a fundamental capability in robotics and has been well studied for recent decades. Although many state-of-the-art algorithms have been proposed, great success usually builds on the assumption that the working environment is static. In most of the real scenes, the assumption cannot hold because there are inevitably moving objects, especially humans, which significantly degrade the localization accuracy. To address this problem, we propose a robust visual localization system building on top of a feature-based visual simultaneous localization and mapping algorithm. We design a dynamic region detection method and use it to preprocess the input frame. The detection process is achieved in a Bayesian framework which considers both the prior knowledge generated from an object detection process and observation information. After getting the detection result, feature points extracted from only the static regions will be used for further visual localization. We performed the experiments on the public TUM data set and our recorded data set, which shows the daily dynamic scenarios. Both qualitative and quantitative results are provided to show the feasibility and effectiveness of the proposed method. Note to Practitioners —This article was motivated by the visual localization problem of mobile robots in dynamic working environments. Visual localization is an important and fundamental capability in robotics. When a mobile robot is in an unknown environment, one important thing is to localize itself using the data collected from the perception sensors. In real scenes, the current localization algorithms often suffer from moving objects. The existence of moving objects, especially humans, brings a lot of noise into the localization process, which poses a big challenge and makes the robotic implementation unstable. In this article, a novel strategy is designed to handle this problem. We leverage both the object detection result and observation information in a Bayesian framework for dynamic region detection. Once the dynamic regions are determined, we discard them and feed the other regions in a state-of-the-art visual simultaneous localization and mapping system for further visual localization. The proposed strategy greatly improves the localization accuracy in dynamic working environments and guarantees the robustness for robotic implementation.

A New Method of Simultaneous Localization and Mapping for Mobile Robots Using Acoustic Landmarks

The simultaneous localization and mapping (SLAM) problem for mobile robots has always been a hotspot in the field of robotics. Simultaneous localization and mapping for robots using visual sensors and laser radar is easily affected by the field of view and ground conditions. According to the problems of traditional sensors applied in SLAM, this paper presents a novel method to perform SLAM using acoustic signals. This method enables robots equipped with sound sources, moving within a working environment and interacting with microphones of interest, to locate itself and map the objects simultaneously. In our case, a method of microphone localization based on a sound source array is proposed, and it was applied as a pre-processing step to the SLAM procedure. A microphone capable of receiving sound signals can be directly used as a feature landmark of a robot observation model without feature extraction. Meanwhile, to eliminate the random error caused by hardware equipment, a sound settled in the middle of two microphones was applied as a calibration sound source to determine the value of the random error. Simulations and realistic experimental results demonstrate the feasibility and effectiveness of the proposed method.

Intelligent Range-Only Mapping and Navigation for Mobile Robots

Addressing the navigation (localization and motion control) problem of a mobile robot, coupled with its mapping problem, remains a significant challenge to date. The well-known simultaneous localization and mapping problem of mobile robots has been addressed in the literature without specifically taking into account the robot's motion control tasks. Moreover, its implementation can cost more than the robot itself. Robot motion control strategies developed in the literature either 1) rely on sophisticated hardware platforms, 2) assume noise-free environment, or 3) are based on abstract theories, which are validated using computer simulations only. The current work solves the navigation and mapping problems of mobile robots using open-source hardware and range-only measurements from a network of radio sources. The hardware platform used in this work is customized such that it is cost-effective and easy-to-implement, addressing the aforementioned issues in developing motion control strategies. The current strategy permits the robot to estimate its position and orientation and builds a map of its operating environment using radio frequency signals received from radio sources. It then navigates through a path defined by a set of two-dimensional points on the ground using a motion control strategy in cooperation with a computational intelligence tool. The proposed robot navigation and mapping scheme was tested in an indoor laboratory environment and its performance was compared with the simulation counterpart using a commercial robot simulator.

Random Set Approach to Distributed Multivehicle SLAM

This paper deals with the simultaneous localization and mapping (SLAM) problem for autonomous vehicles or mobile robots. More specifically, a multi-vehicle scenario is considered wherein a team of vehicles explore the scene of interest in order to cooperatively construct the map of the environment by locally updating and exchanging map information in a neighbor-wise fashion. A random-set approach is undertaken by regarding the map as a random finite set (RFS) and updating the first-order moment, called probability hypothesis density (PHD), of its multi-object density. Consensus on PHDs is adopted in order to spread the map information through the team of vehicles also taking into account the different and time-varying fields of view (FoVs) of the team members. The developed algorithm represents - to the best of the authors’ knowledge - the first attempt to solve in a fully decentralized way the multi-vehicle SLAM problem within the RFS framework. The effectiveness of the proposed approach is tested by means of simulation experiments.

Enhanced Simultaneous Localization and Mapping (ESLAM) for Mobile Robots

FastSLAM, such as FastSLAM 1.0 and FastSLAM 2.0, is a popular algorithm to solve the simultaneous localization and mapping (SLAM) problem for mobile robots. In real environments, however, the execution speed by FastSLAM would be too slow to achieve the objective of real-time design with a satisfactory accuracy because of excessive comparisons of the measurement with all the existing landmarks in particles, particularly when the number of landmarks is drastically increased. In this paper, an enhanced SLAM (ESLAM) is proposed, which uses not only odometer information but also sensor measurements to estimate the robot’s pose in the prediction step. Landmark information that has the maximum likelihood is then used to update the robot’s pose before updating the landmarks’ location. Compared to existing FastSLAM algorithms, the proposed ESLAM algorithm has a better performance in terms of computation efficiency as well as localization and mapping accuracy as demonstrated in the illustrated examples.

Toward Simple Strategy for Optimal Tracking and Localization of Robots With Adaptive Particle Filtering

The ability of robotic systems to autonomously understand and/or navigate in uncertain environments is critically dependent on fairly accurate strategies, which are not always optimally achieved due to effectiveness, computational cost, and parameter settings. In this paper, we propose a novel and simple adaptive strategy to increase the efficiency and drastically reduce the computational effort in particle filters (PFs). The purpose of the adaptive approach (dispersion-based adaptive particle filter—DAPF) is to provide higher number of particles during the initial searching state (when the localization presents greater uncertainty) and fewer particles during the subsequent state (when the localization exhibits less uncertainty). With the aim of studying the dynamical PF behavior regarding others and putting the proposed algorithm into practice, we designed a methodology based on different target applications and a Kinect sensor. The various experiments conducted for both color tracking and mobile robot localization problems served to demonstrate that the DAPF algorithm can be further generalized. As a result, the DAPF approach significantly improved the computational performance over two well-known filtering strategies: 1) the classical PF with fixed particle set sizes, and 2) the adaptive technique named Kullback–Leiber distance.

Information filtering and array algorithms for discrete-time Markovian jump linear systems subject to parametric uncertainties

In this paper we present robust information filters for discrete-time Markovian jump linear systems subject to uncertainties in the parameters. We provide recursive estimations to deal with jumps, uncertainties, and unknown initial conditions of the Markovian states. The difficulty in defining initial conditions for this class of systems where the Markov chain is also unknown, justifies the use of information type filters. As an alternative computation method we develop array and fast array algorithms to estimate these uncertain informations. We present numerical examples to demonstrate the efectiveness of the array algorithms proposed. We present also simulation results related with the application of the robust information filter to solve mobile robot localization problems.

Guaranteed interval analysis localization for mobile robots

This paper presents a set membership method (named Interval Analysis Localization (IAL)) to deal with the global localization problem of mobile robots. By using a LIDAR (LIght Detection And Ranging) range sensor, the odometry and a discrete map of an indoor environment, a robot has to determine its pose (position and orientation) in the map without any knowledge of its initial pose. In a bounded error context, the IAL algorithm searches a set of boxes (interval vector), with a cardinality as small as possible that includes the robot’s pose. The localization process is based on constraint propagation and interval analysis tools, such as bisection and relaxed intersection. The proposed method is validated using real data recorded during the CAROTTE challenge, organized by the French ANR (National Research Agency) and the French DGA (General Delegation of Armament). IAL is then compared with the well-known Monte Carlo Localization showing weaknesses and strengths of both algorithms. As it is shown in this paper with the IAL algorithm, interval analysis can be an efficient tool to solve the global localization problem.

Kullback–Leibler divergence-based global localization for mobile robots

The global localization problem for mobile robots is addressed in this paper. In this field, the most common approaches solve this problem based on the minimization of a quadratic loss function or the maximization of a probability distribution. The distances obtained from the perceptive sensors are used together with the predicted ones (from the estimates in the known map) to define a cost function or a probability to optimize. In our previous work, we developed an optimization-based global localization module that used evolutionary computation concepts. In particular, the algorithm engine was the Differential Evolution method. In this work, this algorithm has been modified including the minimization of the Kullback–Leibler divergence between true observations and estimates. This divergence is used to calculate the cost function of the localization module. The algorithm has been tested in different situations and the most important improvement is the ability to cope with different types of occlusions.

Finite-Horizon $H_{\infty} $ Filtering With Missing Measurements and Quantization Effects

In this paper, a new H∞ filtering approach is developed for a class of discrete time-varying systems subject to missing measurements and quantization effects. The missing measurements are modeled via a diagonal matrix consisting of a series of mutually independent random variables satisfying certain probabilistic distributions on the interval [0,1] . The measured output is quantized by a logarithmic quantizer. Attention is focused on the design of a stochastic H∞ filter such that the H∞ estimation performance is guaranteed over a given finite-horizon in the simultaneous presence of probabilistic missing measurements, quantization effects as well as external non-Gaussian disturbances. A necessary and sufficient condition is first established for the existence of the desired time-varying filters in virtue of the solvability of certain coupled recursive Riccati difference equations (RDEs). Owing to its recursive nature, the proposed RDE approach is shown to be suitable for online application without the need of increasing the problem size. The simulation experiment is carried out for the mobile robot localization problem with non-Gaussian disturbances, missing measurements and quantization effects. The effectiveness of the proposed method is demonstrated in the numerical example.

A Study on Localization Problem of Autonomous Mobile Robot Using Gaussian Mixture Model

A Study on Localization Problem of Autonomous Mobile Robot Using Gaussian Mixture Model

Hybrid adaptive differential evolution for mobile robot localization

This paper introduces a new evolutionary optimization algorithm named hybrid adaptive differential evolution (HADE) and applies it to the mobile robot localization problem. The behaviour of evolutionary algorithms is highly dependent on the parameter selection. This algorithm utilizes an adaptive method to tune the mutation parameter to enhance the rate of convergence and eliminate the need for manual tuning. A hybrid method for mutation is also introduced to give more diversity to the population. This method which constantly switches between two mutation schemes guarantees a sufficient level of diversity to avoid local optima. We use a well-known test set in continuous domain to evaluate HADE's performance against the standard version of differential evolution (DE) and a self-adaptive version of the algorithm. The results show that HADE outperforms DE and self-adaptive DE in three of four benchmarks. Moreover, we investigate the performance of HADE in the well-known localization problem of mobile robots. Results show that HADE is capable of estimating the robot's pose accurately with a decreased number of individuals needed for convergence compared with DE and particle swarm optimization methods. Comparative study exposes HADE algorithm as a competitive method for mobile robot localization.

Reinforcement learning using a swarm intelligence based neural network

This paper proposes a new reinforcement learning method using the SWarm Intelligence-trained Neural Network (SWINN) to efficiently generate solutions to various real-world problems. The swarm intelligence algorithm Particle Swarm Optimization (PSO) is combined with a Training Resource Allocator (TRA) in SWINN for specific problems. TRA, as a heuristic global search method, controls the allocation of training resources to different candidate topologies of artificial neural networks (ANNs) to expedite the system convergence, while PSO is applied as a local search algorithm to adjust the ANN’s connection weights. To evaluate the performance of the SWINN algorithm, two reinforcement learning case studies: the double pole balance (a.k.a. double inverted pendulum) problem and a mobile robot localization problem are conducted. Simulation results successfully demonstrate that SWINN offers performance that is competitive with modern neuroevolutionary techniques, and is viable for real-world problems.